Method and machine for making food patties

ABSTRACT

A meat patty molding machine having a base plate with an opening therethrough and a fill plate rotatably mounted in the base plate opening. A meat feeder forces meat up through openings in the fill plate. A mold plate defines a disk-shaped mold cavity and is mounted to move laterally between a fill position with its disk-shaped mold cavity in communication with the fill plate and a patty discharge position with the disk-shaped mold cavity away from the fill plate. A drive means rotates the fill plate relative to the mold plate, and the fill plate is rotated relative to a stationary cutting blade which is biased against the fill plate by substantial pressure to cut meat fibers at the upstream surface of the fill plate during filling.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of application Ser. No. 404,327,abandoned Feb. 11, 1991, filed Sept. 12, 1989, entitled "Method andMachine for Making Food Patties".

DESCRIPTION

1. Technical Field

The present invention relates to a machine for making a food patty, andparticularly making a hamburger patty of ground meat.

2. Background of the Invention

It is generally known in the art to have a patty molding machine, havinga hopper for holding a supply of ground meat such as ground beef, whichis progressively advanced to a fill position for delivery of the groundmeat into one or more mold cavities in a reciprocal mold plate. Pressureis exerted on the ground meat to fill the mold cavities. After the moldcavities are filled, the mold plate is moved to a knock-out or dischargeposition where the patties can be forced out of the mold cavities forfurther handling.

A variety of such molding machines are well known in the art, as shownin, for example, U.S. Pat. Nos. 2,456,778, 3,378,608, 4,272,864,4,597,134, and 4,768,941. Such machines have formed the meat patties ina variety of ways, and yet present problems such as potential cloggingof the fill plates, overworking the meat, high pressure required to formthe patty, drawing meat back out of the mold after it has been filled,meat patties which will fall apart and shrink unevenly during cooking,and patties which are tough in texture after cooking.

The present invention is directed toward overcoming one or more of theproblems set forth above.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a meat patty molding machine isdisclosed having a base plate with an opening therethrough, with a fillplate rotatably mounted in the base plate opening. A meat feeder isdisposed beneath the base plate and forces meat through openings in thefill plate. A mold plate defines a mold cavity and is mounted to movelaterally relative to the base plate between a fill position with itsmold cavity over the fill plate and a patty discharge position with themold cavity away from the fill plate. A drive means rotates the fillplate relative to the mold plate. The fill plate rotates relative to aknife which is biased by substantial pressure against the fill plate tocut fibers from its bottom surface during filling.

In yet another aspect of the present invention, a method of molding ameat patty is disclosed, including feeding meat into a disk-shaped moldcavity through holes in a fill plate defining one end of the moldcavity, and rotating the fill plate relative to the remainder of themold while feeding the meat through the fill plate holes. The feed sideof the fill plate is cleared by a knife biased thereagainst bysubstantial pressure and disposed substantially perpendicular to thepatty axis by rotating the fill plate relative to the knife.

It is an object of the present invention to provide meat patties whichwill maintain their shape and not fall apart when handled and/or cooked.

It is another object of the present invention to mold meat pattieswithout overworking the meat.

Still another object of one aspect of the present invention is toprovide meat patties which will cook up and shrink uniformly about thecentral axis of the patty to maintain a circular shape and remain flateven after cooking.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross-sectional view of one type of patty makingmachine embodying the present invention;

FIG. 2 is a side view of a food patty formed by the present invention;

FIG. 3 is an side cross-sectional view of the patty-making mold of thepresent invention;

FIG. 4 is a plan view of the patty-making mold of the present inventionwith the fill plate and other structure above the base plate omitted;

FIG. 5 is an enlarged fragmentary cross-sectional view taken along line5--5 in FIG. 4;

FIG. 6 is an enlarged fragmentary cross-sectional view taken along line6--6 of FIG. 4; and

FIG. 7 is an exploded view of a the rotatable fill plate and associatedparts.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The patty molding machine is shown generally in FIG. 1 and may begenerally of the same construction as the machine shown in U.S. Pat.Nos. 4,597,134 and 4,768,941, the disclosures of which are herebyincorporated by reference.

The patty molding machine has a base 10 supporting a hopper 12 thereonin which large quantities of the product to be formed into patties, suchas ground beef, may be placed. While reference herein is made to groundbeef in the formation of hamburger patties, it will be evident that thedisclosed invention applies equally to formation of patties from anyfood product containing material that tends to cook to a misshapen form.

The hopper 12 is preferably in the shape of an inverted cone and has anauger 14 therein extending substantially along the inner wall of thehopper 12 and rotated by a suitable drive mechanism 16. The ram housing18 defines a chamber 20 into which the ground meat 22 can be fed by theauger 14.

As shown in the Figures, the chamber 20 further includes a rectangularportion 24 at its upper end, which portion 24 is disposed directly belowthe molding station 26 as described below. It will be appreciated bythose skilled in the art, however, that a variety of configurations ofthe chamber 20 would be suitable so long as the chamber 20 allows meatto be fed to the molding station 26.

A piston 28 is suitably driven to force the meat 22 up the chamber 20and into the molding station 26 for formation into patties as furtherdescribed below.

It will be appreciated by those skilled in the art that the presentinvention, which relates specifically to the below described moldingstation 26, could be used with a variety of feed mechanisms other thanthat shown in FIG. 1.

The molding station 26, as clearly shown in FIG. 3, includes a baseplate 30 suitably secured to the ram housing 18, as by the bolts 32shown (see particularly FIGS. 1 and 7). The base plate 30 includes acylindrical opening 34 (see FIG. 7) within which is received adisk-shaped or cylindrical fill plate 36 which may rotate about itscentral axis 38 with respect to the base plate 30 as will be described.

The base plate 30 further includes aligned radial slots 40 which receivea blade holder 42 which secures a cutting blade or knife 44 (see FIGS. 6and 7) against rotation with the fill plate 36 as described in greaterdetail further below. The knife 44 includes oppositely facing cuttingedges 45a and 45b (see especially FIGS. 6 and 7) on opposite sides ofthe blade center (which coincides with the fill plate axis 38), whichprovide improved operation as will be described.

The fill plate 36 includes a cylindrical recess 46 within which theknife 44 is received, and a suitable spring, such as the urethane O-ringspring 48 shown in FIGS. 6 and 7, biases the knife 44 up into the fillplate recess 46 and against the bottom of the fill plate 36. The 0-ringspring 48 biases the knife 44 with sufficient force and resultantsubstantial pressure, to ensure proper cutting action as furtherdescribed hereafter.

Disposed on top of the base plate 30 is a mold plate 50 having acylindrical opening 52 defining a cylindrical or disk-shaped mold cavity54. The mold plate 50 is shown as having a single mold cavity 54.However, it is within the scope of the invention to have a plurality oftransversely aligned mold cavities in the mold plate whereby a pluralityof patties can be formed at the molding station 26. Further, whiledisk-shaped cavities provide the preferred shape of molded patty, itshould also be understood that the present invention could also be usedwith different shaped mold cavities, such as square or oval.

Spacer plates 56 are fixed to the top of the base plate 30 on oppositesides of the mold plate 50 so as to define a channel within which themold plate 50 may slide in operation. That is, as hereafter described,the mold plate 50 can be moved laterally between a fill position overthe fill plate 36 (as shown in FIG. 3) and a knock-out or dischargeposition spaced from the fill plate 36. Spacer plates 56 havingdifferent thicknesses (heights) may be used according to the desiredthickness of the molded meat patty (and thus the thickness of the moldplate 50), as will become apparent.

A top or header plate 60 (see FIG. 3) is secured to the tops of thespacer plates 56 and over the mold plate 50 to define the top of themold cavity 54 (as well as defining the top of the channel allowinglateral movement of the mold plate 50.

A meat collector 64 (see FIG. 4) may also be provided beneath themolding station 26. This collector 64 is essentially a trough whichcatches meat 22 which may leak out from between the plates of themolding station 26.

A drive motor 70 is suitably mounted to the molding station 26, as bythe pivotable bracket 72 shown in FIGS. 4 and 7. A suitable lockingmechanism, such as the quick disconnect pin mechanism 74 shown in FIG.4, is provided to secure the motor 70 in position during operation,while also allowing the motor 70 to be pivoted clear of the moldingstation 26 during servicing or the like.

The motor 70 drives a worm 76 which extends into a bore 78 in the baseplate 30. A suitable coupling 80 is provided between the worm 76 and themotor 70 to transmit the drive forces to the worm 76 while also allowingthe motor 70 to be pivoted clear of the molding station 26 as previouslydescribed.

It will be understood by those skilled in the art, however, that thedrive mechanism shown in the drawings is merely one which would besuitable for rotating the fill plate 36, and any number of other suchmechanisms could also be used advantageously.

Referring now specifically to the fill plate 36, a worm gear 86 isprovided around its outer periphery, which gear 86 engages the worm 76(see FIG. 5) so that the fill plate is rotated about its axis 38 duringoperation.

The fill plate 36 further has a plurality of fill openings 88 to allowpassage therethrough of meat 22 from the chamber rectangular portion 24to the mold cavity 54 as further described hereafter. The fill openings88 are preferably round and vertical (that is, at right angles to theupper and bottom surfaces of the fill plate 36). Such openings 88 allowfor a large fill area over the fill plate 36 (more fill area thanallowed with the traditional straight slots fill openings of the priorart). This large fill area, as well as the vertical orientation of theopenings 88 (requiring a minimum feed distance through the plate 36),allow meat 22 to be fed into the mold cavity 54 by using low pressures,thereby minimizing both power requirements and reworking of the meat 22.Of course, still other shapes and orientations of the openings 88 couldbe used advantageously within the scope of the present invention.

It should be appreciated by those skilled in the art that different fillplates, having different size and spaced openings, can be interchangedwith the present invention depending on the type of meat 22 beingmolded.

It should also be appreciated by those skilled in the art that the abovepatty molding machine can be easily operated. Further, the above machinecan be easily cleaned with removal of a minimal number of parts, asignificant factor for machines such as this requiring frequentcleaning. To further enhance the easy cleaning capabilities of thisinvention, the worm 76 is preferably oriented so that it essentially isself threading on the worm gear 86 when it is inserted into the bore 78during reassembly after cleaning.

Operation of the above described patty molding machine is as follows.

The auger 14 is suitably driven to force meat 22 from the hopper 12 intothe feed chamber 20. The piston 28 reciprocates up and down so that, onits up stroke, it forces meat into the chamber portion 24 directlybeneath the fill plate 36. The pressure from the piston 28 causes themeat 22 to be forced up against the bottom of the fill plate 36, and tothereby force its way through the fill openings 88 in the fill plate 36(as shown particularly in FIG. 5).

As the meat 22 is forced through the fill plate openings 88, the fillplate 36 is also being rotated about its axis 38 by the drive motor 70through the interaction of the worm 76 and the fill plate worm gear 86.

It has been found that rotating the fill plate 36 at a rate of 45revolutions per minute with fill times of less than a second (andapproximately 90 degree rotation of the fill plate 36 during fill) canbe suitable for some meats. Increasing the speed of rotation of the fillplate 36 will cause tighter patties to be made, whereas decreasing therotation speed will result in looser molded patties.

Further, as the fill plate 36 rotates, the stationary knife 44 cuts themeat fibers extending from the bottom (or upstream side) of the fillplate 36. This prevents clogging of the openings 88 by cutting entangledmeat fibers between the openings 88, and further prevents meat 22 frombeing drawn back out of the mold cavity 54 by cutting meat strands atthe bottom of the fill plate 36. Also, inasmuch as the knife 44 isessentially stationary relative to the meat 22 (that is, though the meat22 goes past the blade 44, the blade 44 does not move through the meat22 laterally to the feed direction), undesirable reworking of the meat22 which is molded into the patties is minimized. Further, thesubstantial pressure provided by the 0-ring spring 48 biasing the knife44 against the bottom surface of the fill plate 36, ensures propercutting action on the meat. For example, it has been found that a forceof 400 lbs. with a knife 44 having a contact surface of 0.16 sq. in.(resulting in an advantageous pressure of 2,500 psi) provides goodresults by ensuring complete severing of the strands of meat whichotherwise would accumulate on the bottom of the fill plate 36 and clogup its openings 88. Of course, in order to obtain a substantial pressureas described above, a different knife design should be biased by aproportionately greater or lesser force depending on its contact surface(for example, a knife having twice the contact surface would preferrablybe biased with twice the force to provide the same substantialpressure).

Still further, the blade 44 is stable during operation due to itsoppositely facing cutting edges 45a and 45b on opposite sides of theaxis 38. That is, not only are lateral forces on the blade 44 minimizeddue to its essentially stationary position relative to the meat 22, butthe tendency of each cutting edge 45a or 45b of the blade 44 to tipbackwards is counteracted by the generally equal but opposite forceencountered by the oppositely facing edge 45b or 45a.

When the mold cavity 54 is filled with meat 22, a patty is formed withthe meat 22 laid in an essentially circular/spiral pattern. The moldplate 50 is then moved laterally between the spacer plates 56, so thatthe mold plate cylindrical opening 52 is spaced from the molding station26 and in a discharge position. During such movement, the patty iscarried with the mold plate 50 while sliding over the base plate 30 andunder the header plate 60. This sliding motion further helps to keep thepatty in its shape by entangling meat fibers on the top and bottom ofthe patty, effectively binding the patty together.

The patty is then ejected from the mold plate 50 by suitable means, andthe patty is used or packaged as desired. The mold plate 50 is thenretracted to position its cylindrical opening 52 back over the fillplate 36 for formation of another patty.

Meat patties 100 formed such as disclosed above (and such as shown inFIG. 2) are stable and secure against breaking apart during handlingand/or cooking. Also, meat patties 100 having a circular/spiral patternto their meat strands are formed symmetrically about their center, withsubstantially uniform density of the meat 22.

Further, meat patties 100 having such a configuration result in an ideal"cook out", with the patties shrinking uniformly about their center.Further, where the patties 100 are circular, as is the most frequent anddesirable shape, such uniform shrinking ensures that the patties 100maintain their desired circular shape even after cooking

It will be appreciated that, where the fill plate 36 rotates only about90 degrees during formation of a patty 100, the knife 44 shown in thefigures will not fully cut the meat fibers extending from the bottom ofthe fill plate 36. The cutting action which is accomplished by suchoperation has nevertheless been found to be sufficient to provide theadvantages of this invention as described above. However, should a fullcutting action be desired, it will be appreciated by those skilled inthe art that the rotation of the fill plate 36 during formation of thepatty 100 can be increased to 180 degrees or, alternatively, a knifehaving an X-configuration (with 90 degrees between legs) could also beprovided within the scope of the present invention.

Other aspects, objects, and advantages of the present invention can beobtained from a study of the specification, drawings and appendedclaims.

I claim:
 1. A meat patty molding machine comprising:a fill plate havinga substantially flat surface thereon and having openings therethrough;means for defining a disk-shaped mold cavity on said fill plate; meansfor feeding meat through said fill plate openings into the defined moldcavity; means for rotating one of said fill plate or said mold cavitydefining means relative to the other during feeding of said meat; acutting blade mounted to cut meat on the side opposite the fill plateflat surface during feeding of said meat; and means for biasing saidcutting blade against the fill plate with a substantial force.
 2. Themeat patty molding machine of claim 1, wherein the relative rotation ofsaid fill plate and said mold cavity defining means occurs substantiallyabout an axis perpendicular to said fill plate and centrally locatedrelative to said mold cavity.
 3. The meat patty molding machine of claim1, wherein:said fill plate is rotatably mounted to a base plate and issubstantially circular with a gear surface therearound; and saidrotating means comprises a gear drive engaging said fill plate gearsurface.
 4. The meat patty molding machine of claim 3, furthercomprising means for removably mounting said fill plate with respect tosaid base plate, whereby a plurality of fill plates may be substitutedwith different openings adapted to suit the particular meat beingmolded.
 5. The meat patty molding machine of claim 3, wherein said geardrive is a worm gear.
 6. The meat patty molding machine of claim 5,wherein said worm gear extends into an opening through said base plate,said worm gear being driven by a motor mounted to said base plate. 7.The meat patty molding machine of claim 1, wherein:said fill plate ismounted to a base plate and rotates with respect to said base plateduring feeding of said meat; and said cutting blade is fixed againstrotation relative to said base plate.
 8. The meat patty molding machineof claim 1, wherein said biasing means comprises an O-ring spring. 9.The meat patty molding machine of claim 1, wherein said cutting blade isbiased against the fill plate to produce a pressure therebetween of atleast 2,000 psi.
 10. The meat patty molding machine of claim 1, whereinsaid cutting blade is biased against the fill plate to produce apressure therebetween of at least 2,500 psi.
 11. The meat patty moldingmachine of claim 1, wherein said fill plate openings are substantiallyperpendicular to said fill plate flat surface.
 12. The meat pattymolding machine of claim 1, wherein:said disk-shaped mold cavity iscentered about an axis perpendicular to said fill plate; and the fillplate and the mold cavity defining means rotate at least 45 degreesabout said axis relative to one another during the feeding of said meat.13. The meat patty molding machine of claim 1wherein said disk-shapedmold cavity is centered about an axis perpendicular to said fill plate,whereby the relative rotation of said fill plate and said mold cavitydefining means occurs substantially about said axis; and wherein saidcutting blade is mounted perpendicular to said axis.
 14. A meat pattymolding machine, comprising:means for feeding meat; a base platedisposed over said meat feeding means and having an openingtherethrough; a fill plate having openings between its top and bottomsurfaces allowing meat to pass therethrough, said fill plate beingrotatably mounted in said base plate opening; a mold plate defining adisk-shaped mold cavity, said mold plate being mounted to move laterallybetween a fill position with its disk-shaped mold cavity over said fillplate and a patty discharge position with its disk-shaped mold cavityaway from said fill plate; means for rotating said fill plate and saidmold plate relative to one another when said mold plate is in its fillposition; a cutting blade mounted to cut at the bottom surface of thefill plate during feeding of said meat; and means for biasing saidcutting blade to produce substantial pressure between the cutting bladeand the fill plate.
 15. The meat patty molding machine of claim 14,wherein said disk-shaped mold cavity is substantially cylindrical aboutan axis perpendicular to said fill plate when said mold plate is in itsfill position, whereby the relative rotation of said fill plate and saidmold plate occurs substantially about said axis.
 16. The meat pattymolding machine of claim 14, wherein said fill plate top surface definesthe bottom surface of the defined mold cavity and said feeding meanscomprises a piston disposed beneath the base and fill plates.
 17. Themeat patty molding machine of claim 14, wherein:said fill plate issubstantially circular with a gear surface therearound; and saidrotating means comprises a gear drive engaging said fill plate gearsurface.
 18. The meat patty molding machine of claim 17, furthercomprising means for removably mounting said fill plate with respect tosaid base plate, whereby a plurality of fill plates may be substitutedwith different openings adapted to suit the particular meat beingmolded.
 19. The meat patty molding machine of claim 17, wherein saidgear drive is a worm gear.
 20. The meat patty molding machine of claim19, wherein said worm gear extends into a second opening through saidbase plate, said worm gear being driven by a motor mounted to said baseplate.
 21. The meat patty molding machine of claim 14, wherein:said fillplate rotates with respect to said base plate during feeding of saidmeat; and said cutting blade is fixed against rotation relative to saidbase plate.
 22. The meat patty molding machine of claim 14, wherein saidbiasing means comprises an O-ring spring.
 23. The meat patty moldingmachine of claim 14, wherein said cutting blade is biased against thefill plate to produce a pressure therebetween of at least 2,000 psi. 24.The meat patty molding machine of claim 14, wherein said cutting bladeis biased against the fill plate to produce a pressure therebetween ofat least 2,500 psi.
 25. The meat patty molding machine of claim 14,wherein said fill plate openings are substantially perpendicular to saidfill plate flat surface.
 26. The meat patty molding machine of claim 14,wherein:said disk-shaped mold cavity is centered about an axisperpendicular to said fill plate; and the fill plate and the mold platerotate at least 45 degrees about said axis relative to one another whensaid mold plate is in its fill position.
 27. The meat patty moldingmachine of claim 14,wherein the relative rotation of said fill plate andsaid mold plate occurs substantially about an axis perpendicular to saidfill plate and centrally located relative to said mold cavity when saidmold plate is in its fill position; and wherein said cutting blade ismounted perpendicular to said axis.
 28. A meat patty molding machine,comprising:a base plate having an opening therethrough; means forfeeding meat from the bottom of the base plate; a fill plate disposed inthe base plate opening, said fill plate being substantiallycylindrically shaped with top and bottom flat surfaces on opposite endsof a circular outer surface, said fill plate further havingsubstantially vertical openings between the top and bottom flat surfacesallowing passage therethrough of meat from the feeding means; a moldplate reciprocable between fill and discharge positions, said mold platedefining a disk-shaped mold cavity over the top flat surface of the fillplate when said mold plate is in its fill position, said mold cavityfurther having a central axis substantially perpendicular to said fillplate; a substantially longitudinal cutting blade fixedly positionedrelative to the base plate to intersect said axis at substantially rightangles when said mold plate is in its fill position; drive means forrotating the fill plate about the axis relative to the base plate whenthe mold plate is in the fill position; a cutting blade mounted to cutmeat on the side opposite the fill plate flat surface during feeding ofsaid meat; and means for biasing said cutting blade against said fillplate to produce substantial pressure between the cutting blade and thefill plate.
 29. A method of molding a meat patty, comprising the stepsof:feeding meat into a disk-shaped mold cavity through holes in a fillplate defining one surface of the mold cavity; rotating said fill platerelative to the remainder of the mold cavity while feeding the meatthrough the fill plate holes; biasing a cutting blade against the feedside of the fill plate to produce substantial pressure therebetween; androtating said fill plate relative to said blade.
 30. The method of claim29, wherein the disk-shaped mold cavity is substantially cylindricalabout an axis, and said relative rotation occurs about said axis. 31.The method of claim 29, wherein the cutting blade is biased against thefill plate to produce a pressure therebetween of at least 2,000 psi. 32.The method of claim 29, wherein the cutting blade is biased against thefill plate to produce a pressure therebetween of at least 2,500 psi. 33.The method of claim 29, wherein said relative rotation occurs through anangle of at least 45 degrees during feeding.
 34. The method of claim 29,wherein the remainder of the mold cavity remains substantiallystationary during the feeding step and while the fill plate is rotated.